Make Low Stock stat card clickable to filter inventory by low stock items

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/PowderCoating.Web/Views/Inventory/Index.cshtml

@@ -44,11 +44,21 @@
     </div>
 
     <div class="col-md-3">
-        <div class="card border-0 shadow-sm">
+        <a asp-action="Index" asp-route-lowStockOnly="true" class="text-decoration-none"
+           title="Click to filter list to low stock items">
+            @{ var _lowStockActive = (bool)(ViewBag.LowStockOnly ?? false); }
+            <div class="card border-0 shadow-sm @(_lowStockActive ? "border-danger border" : "")"
+                 style="cursor:pointer;transition:box-shadow .15s;">
                 <div class="card-body">
                     <div class="d-flex justify-content-between align-items-center">
                         <div>
-                        <p class="text-muted mb-1" style="font-size: 0.875rem;">Low Stock Items</p>
+                            <p class="text-muted mb-1" style="font-size: 0.875rem;">
+                                Low Stock Items
+                                @if (lowStockCount > 0)
+                                {
+                                    <i class="bi bi-funnel-fill ms-1 text-danger" style="font-size:.7rem;" title="Click to filter"></i>
+                                }
+                            </p>
                             <h3 class="mb-0 fw-bold @(lowStockCount > 0 ? "text-danger" : "")">@lowStockCount</h3>
                         </div>
                         <div class="rounded-circle p-3" style="background: #fee2e2;">
@@ -57,6 +67,7 @@
                     </div>
                 </div>
             </div>
+        </a>
     </div>
 
     <div class="col-md-3">
@@ -102,11 +113,13 @@
                 <div class="stat-value">@Model.TotalCount</div>
                 <div class="stat-label">Total</div>
             </div>
-            <div class="stat-item">
+            <a asp-action="Index" asp-route-lowStockOnly="true" class="text-decoration-none">
+            <div class="stat-item" style="cursor:pointer;">
                 <div class="stat-icon"><i class="bi bi-exclamation-triangle text-danger"></i></div>
                 <div class="stat-value @(lowStockCount > 0 ? "text-danger" : "")">@lowStockCount</div>
                 <div class="stat-label">Low Stock</div>
             </div>
+            </a>
             <div class="stat-item">
                 <div class="stat-icon"><i class="bi bi-check-circle text-success"></i></div>
                 <div class="stat-value">@activeCount</div>